ext4: online defrag -- Add EXT4_IOC_MOVE_EXT ioctl
The EXT4_IOC_MOVE_EXT exchanges the blocks between orig_fd and donor_fd,
and then write the file data of orig_fd to donor_fd.
ext4_mext_move_extent() is the main fucntion of ext4 online defrag,
and this patch includes all functions related to ext4 online defrag.
Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 91e75f7..bb415408 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -14,6 +14,7 @@
#include <linux/compat.h>
#include <linux/smp_lock.h>
#include <linux/mount.h>
+#include <linux/file.h>
#include <asm/uaccess.h>
#include "ext4_jbd2.h"
#include "ext4.h"
@@ -213,6 +214,41 @@
return err;
}
+
+ case EXT4_IOC_MOVE_EXT: {
+ struct move_extent me;
+ struct file *donor_filp;
+ int err;
+
+ if (copy_from_user(&me,
+ (struct move_extent __user *)arg, sizeof(me)))
+ return -EFAULT;
+
+ donor_filp = fget(me.donor_fd);
+ if (!donor_filp)
+ return -EBADF;
+
+ if (!capable(CAP_DAC_OVERRIDE)) {
+ if ((current->real_cred->fsuid != inode->i_uid) ||
+ !(inode->i_mode & S_IRUSR) ||
+ !(donor_filp->f_dentry->d_inode->i_mode &
+ S_IRUSR)) {
+ fput(donor_filp);
+ return -EACCES;
+ }
+ }
+
+ err = ext4_move_extents(filp, donor_filp, me.orig_start,
+ me.donor_start, me.len, &me.moved_len);
+ fput(donor_filp);
+
+ if (!err)
+ if (copy_to_user((struct move_extent *)arg,
+ &me, sizeof(me)))
+ return -EFAULT;
+ return err;
+ }
+
case EXT4_IOC_GROUP_ADD: {
struct ext4_new_group_data input;
struct super_block *sb = inode->i_sb;